The invention relates in general to filtration and liquid/liquid and gas/liquid separation, and in particular, to an assembly for removing solids, liquids and/or gases from a liquid or gas flow.
More specifically, without restriction to the particular use which is shown and described, this invention relates to an improved filter assembly and cartridge to subject a liquid or gas to filtering, coalescing, and separation to remove solids, emulsified liquids and/or gases therefrom. The invention of the application includes a replacable cartridge capable of superior filtering and separation to return a purified liquid or gas to a fluid system.
In numerous situations, a continuous liquid or gas phase is subject to the accumulation of contaminants in the form of solid particles, liquids and/or gases, which must be subjected to filtration and separation as attempted by numerous techniques of the prior art. The contaminating material may, for example, be present as a solid, liquid, or gas within a gas media, or dispersed as a solid, liquid or gas within a liquid. In one specific situation, the presence of foreign matter is prevalant in the fuel system used in conjunction with vehicle engines of many types. The oil in the fuel system of a diesel engine is particularly vulnerable to the presence of contaminants. Such contaminants in diesel fuel may be in the form of solids, such as dirt, rust particles and the like, or constitute water existing as a dispersed phase within the fuel. Fuels, such as diesel oil, demonstrate a natural affinity to water, because of which water is commonly emulsified within the fluid. The normal turbulent nature of a conventional pump acting to deliver fuel to the engine contributes to the emulsified nature of the water particles within the continuous fuel phase. This widely dispersed liquid is generally difficult to separate from the fluid in such an emulsified state. The presence of contaminating solids and dispersed liquids within the continuous fuel phase is capable of interfering with the efficient operation of the engine and require removal from the fuel.
Many devices have been employed in the prior art in an effort to effectively remove or reduce the amount of contaminating solids, liquids and/or gases, present in liquids or gas, such as, for example, in the form of diesel oils and the like. One type of well known purifying technique used in conjunction with the fuel line of a vehicle applies filtering elements as a means to purify the fuel for satisfactory utilization by the engine. Filtration alone, however, is not effective in removing the contaminating liquids dispersed throughout the fuel, although filtering can, in certain situations, be effective for removing solids. Other prior art devices have been directed to centrifugal type systems by which separation of contaminants from the fuel is obtained by subjecting the fluid to a swirling action. Although such techniques are capable of a degree of satisfactory separation of foreign material from a fluid, these devices do not offer an efficient and relatively inexpensive approach to the problem of removal of contaminants.
Many devices in the prior art have relied upon the phenomenon of coalescing dispersed liquid from a fluid as a means to overcome the problems inherent in the accumulation of liquid in a fuel line. Such coalescing devices rely on a coalescing material to coalesce the liquids into droplets which are more readily separated from the fuel than in the dispersed state. The prior art coalescing devices have been deficient in providing an economical and trouble free device that is capable of highly efficient removal of dispersed liquids in all demand ranges of the vehicle engine. Some of the prior art devices may operate satisfactory at low flow rates through the separator, but as the engine output increases, the flow rate becomes greater and efficiency of coalescing and separation then suffers in such devices resulting in water particles, and the like, being delivered to the engine. The overall deficiency of such coalescing systems has resulted, in part, from the ineffective cooperation between the incoming flow and the coalescing stage.
Moreover, known coalescing-type apparatus have failed to provide or not provided sufficient filtration of solids prior to entry to the coalescing stage, because of which the coalescing operation becomes less efficient due to the interfering presence of solids. The prior art coalescing devices have not further provided effective filtration and separation at all flow rates through the separator, with a resulting decrease of efficiency. Accordingly, the known techniques of filtering and separating contaminants from a fluid, such as a diesel oil and the like, have not attained the optimum level of efficiency to accomplish removal of solids, dispersed liquids and gases from a fuel at all demand levels of the engine.